溶剂分级木质素对ABE发酵液吸附分离性能

Study on adsorption and separation performance of solvent-fractionation lignin on ABE fermentation

运用溶剂分级的方法制备成本低廉、环境友好型木质素基吸附材料,探究了其对ABE发酵液的吸附分离性能。研究发现经丙酮溶解分级后的丙酮不溶木质素(AIAL)具有良好的吸附性能。吸附动力学实验表明AIAL的动态吸附过程在40 min可以达到平衡,数据可用Lagergren拟一级动力学模型拟合;等温吸附实验表明AIAL对丁醇、丙酮和乙醇饱和吸附量分别为198,151.3和98.5 mg/g,较分级前提升了19.3%,30.2%和53.2%,数据可用Langmuir-Freundlich模型拟合;模拟发酵液中的吸附实验表明丁醇、丙酮和乙醇之间竞争吸附作用较小;脱附液中ABE质量浓度达到90.75 g/L;表征分析结果表明:AIAL和丁醇、丙酮和乙醇容易形成π体系。

Acetone was used to fractionate lignin to prepare the environmentally friendly adsorbent.Compared with the unclassified lignin,the adsorption performance of AIAL was enhanced to a certain degree.The kinetic experiments show that the adsorption process reaches equilibrium at 40 min and the pseudo-first-order kinetic equation could predict the process well.Equilibrium experiments indicate that the maximum adsorption capacities of AIAL on butanol,acetone and ethanol are 198,151.3 and 98.5 mg/g,increased by 19.3%,30.2% and 53.2%,respectively,and the data could be fitted by Langmuir-Freundlich model.Isothermal adsorption experiments in simulated fermentation broth show that the competitive adsorption between butanol,acetone and ethanol is slight.The mass concentration of ABE in the condensate reaches 90.75 g/L.The results of characterization analysis show that the AIAL would easily form aπ-system with butanol,acetone and ethanol.